1. Field of the Invention
This invention relates to arrangements for measuring polarization mode dispersion (PMD) in optical communication fibers. More specifically, the invention relates to arrangements for determining which portion of fiber communication system penalty is induced by first-order and all-order PMD.
2. Background Art
Optical fiber communications systems are subject to system penalties that derive from a variety of sources, only one of which is polarization mode dispersion (PMD). Other sources that can degrade system performance include, for example, chromatic dispersion, multi-path interference and nonlinear effects.
When a fiber's performance has been inadequate or failing, conventional systems have not been able to readily isolate the causes of any performance degradation, or measure the relative contributions of the degradation sources. It has sometimes been necessary to bring a system offline in order to perform experiments that can isolate the cause of a problem. This inability to readily diagnose the problem source(s) has thwarted predictions of system performance and prevented efficient and focused attempts to correct performance problems.
Thus, there is a need in the art to readily monitor and evaluate PMD-induced effects in optical transmission systems, to allow system outages to be predicted, corrected or prevented.